The present invention relates to a substrate processing chamber component and methods of manufacturing the same.
In processing of a substrate in a process chamber, as in the manufacture of integrated circuits and displays, the substrate is typically exposed to energized gases that are capable of, for example, etching or depositing material on the substrate. The energized gases can also be provided to clean surfaces of the chamber. However, the energized gases can often comprise corrosive halogen-containing gases and other energized species that can erode components of the chamber, such as the chamber enclosure wall. For example, chamber components made of aluminum can chemically react with energized halogen-containing gases to form AlCl3 or AlF3, thereby corroding the components. The corroded portions of the components can flake off and contaminate the substrate, which reduces the substrate yield. Thus, the corroded components must often be replaced or removed from the chamber and cleaned, resulting in undesirable chamber downtime.
The corrosion resistance of a chamber component can be improved by forming a coating of a corrosion resistant material over surfaces of component that are susceptible to erosion, such as surfaces that would otherwise be exposed to the energized gas. The corrosion resistant coating can be formed by methods such as plasma spraying or thermal spraying coating material onto the surface of an underlying structure of the component. For example, a coating of aluminum oxide can be plasma sprayed onto the surface of an aluminum chamber wall to form a coating that exhibits improved corrosion resistance.
However, while such coatings improve the corrosion resistance of the chamber components, the components having the coatings can exhibit other problems during chamber processes. For example, thermal expansion mismatch between the coating and underlying component structure can lead to stresses at the interface between the coating and underlying structure that causes the coating to flake off the underlying structure, thereby exposing the underlying structure to the corrosive energized gas. The particles of loose coating material can also deposit on and contaminate the substrates being processed in the chamber. The thermal expansion mismatch problem is further exacerbated if there is frequent thermal cycling between or during substrate processing steps.
Thus, there is a need for a chamber and chamber components that exhibit improved corrosion or erosion resistance to energized gases. There is a further need for durable chamber components that are not easily susceptible to flaking off during operation of the chamber, especially when the chamber is subjected to thermal cycling.